EFFECT OF PANICLE INITIATION STAGE SUBMERGENCE ON THE REPRODUCTIVE BEHAVIOR AND YIELD OF DIFFERENT RICE VARIETIES

Abstract

A pot experiment was carried out at the research farm of Sher-e-Bangla Agricultural University, Dhaka with four replications following randomized complete block design during Aman season of 2018 to find out the effect of panicle initiation stage submergence on plants morphological and physiological characters. The experiment comprised of two factors as follows: factor A: variety (four tolerant varieties, V - FR 13A, V 3 - BRRI dhan51, V 4 - BRRI dhan79, V 5 - Binadhan-11 and one susceptible V - BR5), factor B: four submergence treatments (S 0 - control, S - 4 days submergence, S 2 - 7 days submergence, S 3 1 - 10 days submergence). Study reflected that all the parameters were significantly influenced by combined effect of variety and submergence except plant height at 20, 40 DAT and at harvest, 1% panicle emergence stage and 100 grain weight plant -1 . The highest number of tillers plant , 1%, 50%, 100% panicle emergence stage, number of ineffective tillers plant , number of unfilled grains plant -1 , number of unfilled grains panicle and weight of unfilled grains panicle -1 were found in the treatment V 2 S . The highest plant height, SPAD value after desubmergence were found in V 2 S 1 3 . The highest number of fresh leaves plant -1 , total biomass plant -1 was found in V 1 S . The highest number of filled grains plant -1 and panicle -1 were found in V 2 S 0 0 . The highest number of rotten leaves plant -1 , effective tillers plant -1 , panicle length plant -1 -1 , panicle weight plant , oven dry weight of leaf blade plant -1 ,oven dry weight of leaf sheath with stem plant , oven dry weight of root plant -1 were found in V 3 S 3 , V 1 S 3 , V 5 S treatment respectively. The highest weight of filled grains plant 0 , V 4 S 0 , V 1 S 2 -1 , V and 100 grains weight plant -1 were found in V 4 S 0 and V 1 S treatment. As grain yield is the ultimate goal of rice production so the variety which shows less reduction despite being submerged can be suggested for cultivation. The lowest reduction (17.91%) in yield compared to control was found in BRRI dhan51 followed by Binadhan-11 (18.29%). But when submergence duration is more than 7 days Binadhan-11 can be suggested which tolerates submergence up to 10 days. Though the weight of filled grains plant 1

was highest in BRRI dhan79 but its ultimate yield reduction is more (31.78%) than other tolerant varieties due to the effect of panicle initiation stage submergence. 2 -1 -1 S 2 1 and V 5 2 -1 -1 S 0 -1